Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
sach hay » sach han, sach ha, sach nay
dia danh » dia ban, gia dinh
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
va phuc » van phuc, va thuc, xa phuc
quan va » quan vi, quan ha, luan va
lang xa » dang xay, lang van
lang ha » long ha
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach hay ((lang xa) OR (lang ha)) hoi. hieu quan va phuc ((va hanh) or (dia danh)) vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hay ((lang xa) OR (lang ha)) hoi. hieu quan va phuc ((va hanh) OR (dia danh)) vi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach hay ((lang xa) OR (lang ha)) hoi. hieu quan va phuc ((va hanh) or (dia danh)) vi cua tu".
• Adding a wildcard symbol may retrieve word variants: tu sach hay ((lang xa) OR (lang ha)) hoi. hieu quan va phuc ((va hanh) or (dia danh)) vi cua tu*.